Abstract : Literature on the quality of water for mixing and curing concrete indicates that relatively few investigations on this subject have been conducted. It seems to have been generally agreed that water fit to drink was fit to use in concrete mixing, and even fewer limitations were applicable to curing-water quality. Tests were conducted by the Missouri River, South Atlantic, and Ohio River Division Laboratories, and the Waterways Experiment Station to determine the effects of pH values of water on the strength of concrete and the staining properties of elements found in water. It was found that various contaminants can render distilled water unfit for mixing or curing concrete. It is also indicated that pH does not provide a basis for specifying quality of mixing water. A procedure for evaluating curing waters for staining properties is presented in appendix A in which, for a preliminary evaluation, 3000 ml of the water are evaporated, and for a complete test 3 gal are evaporated. A digest of the literature is given in appendix B. (Author)